State school pupils should be given lessons in debating and interview techniques to improve their speaking skills, the shadow education secretary said on Wednesday.
An ability to communicate clearly is vital if they are to compete with their privately-educated peers for the best jobs and university places, according to Stephen Twigg.
Speaking at Paddington Academy, Twigg warned that there has been a lack of focus on speaking skills in schools.
"If we are to break down the barriers that stop some bright young people succeeding, then being articulate and confident is critical," he said.
"Spoken skills have not had enough of a focus within state schools but it is clear this needs to change. We know that many private schools focus on debating and on interview coaching, helping their students get another leg up toward the best universities and jobs.
"Labour wants all pupils to have the same opportunities to develop their verbal communication and presentation skills. This is about modernising our schools system to improve life chances. Aligning the school curriculum with the needs of the modern labour market is essential.
"Young people get the best start when they can communicate with confidence."
Labour said research has shown that in poorer areas, there can be more than 17 children in each class with language skills below their average age.
Private school pupils are more likely to practise debating, with fee-paying schools disproportionately represented in national and international debating competitions.
Young people are held back from achieving their full potential if they are unable to communicate effectively, Labour added.
Twigg's comments come just weeks after Education Secretary Michael Gove said that private school graduates are still dominating positions of wealth and power in the UK's "profoundly unequal" society.
In a speech at Brighton College, he raised concerns that parentage is still dictating a youngster's progress, with poor children likely to stay poor while the rich remain rich.
Private schools are also "handsomely represented" in the Supreme Court, the medical profession, in universities, the media and businesses, Mr Gove said, while many Cabinet ministers and members of the shadow cabinet, along with a large number of celebrities, were educated privately.